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This paper presents a detailed process for the design of interior permanent magnet synchronous machines (IPMSMs) for electric vehicle (EV) applications. First, a comprehensive design process featuring two objectives and three constraints is proposed to realize an optimal IPMSM design that can satisfy the key performance requirements for an EV application. The objectives and constraints were carefully selected and designed to obtain a balance between performance, efficiency, and cost. Because the inductances and magnet flux linkage of the machine are key design parameters for attaining optimal flux-weakening capability, the impact of the machine dimensions on these two parameters is thoroughly investigated and explained using both analytical and numerical techniques. Additional analyses including normalized key performance metrics and the impact of short-circuit faults in PM machines with three different characteristic current values (1, 1.3, and 2.6 pu) are also provided, highlighting the advantages and limitations of the three baseline designs.

In the back electromotive force (EMF)-based sensorless control of interior permanent magnet synchronous motor (IPMSM), the inverter nonlinearity and flux linkage spatial harmonics will possibly give rise to (6 k ± 1)th harmonics in the estimated back EMF, especially the fifth and seventh harmonics. Those harmonics will consequently introduce (6 k )th harmonic ripples to the estimated rotor position, especially the sixth harmonic component. In order to solve this problem, a bilinear recursive least squares (BRLS) adaptive filter is proposed and integrated into a sliding-mode position observer to suppress the dominant harmonic components in the estimated back EMF and as a result, the accuracy of the estimated rotor position can be greatly improved. A unique feature of the BRLS adaptive filter is its ability to track and suppress the specified harmonic components in different steady state and dynamic operational conditions. The proposed method can compensate for harmonic ripples caused by the inverter nonlinearity and machine spatial harmonics at the same time; this method is also robust to machine parameter variation, and the BRLS algorithm itself is machine parameter independent. The implementation of the proposed BRLS filter in the sensorless control of IPMSM is explained in details in this paper. The enhanced drive performances using the BRLS filter have been thoroughly validated in different steady state and dynamic operational conditions on a 1.5-kW IPMSM sensorless drive.

Referring to the sensorless control of interior permanent magnet synchronous motor (IPMSM), the initial rotor polarity is normally estimated based on the motor saturation effect. However, for certain special IPMSMs, the saturation effect is weak even at the rated point, making the saturation-based rotor polarity detection methods invalid. Therefore, this paper proposes a novel rotor polarity detection method based on torque-pulse injection. Two current pulses are imposed on the positive and negative directions of the q-axis estimated by the high-frequency injection (HFI) method, respectively; the signs of speed peaks indicate the rotor polarity. To derive the rotor polarity from the tiny speed signal, a new speed estimation method is presented. To improve the dynamic performance of speed estimation, a special current filter is adopted in the HFI method. To choose the proper width and amplitude of the current pulse under different load and inertia conditions, an automatic program is designed. The proposed method has the advantages of high accuracy, short identification time, tiny movement, and automatic operation, making it applicable to various load and inertia conditions. The effectiveness of the proposed method is validated by experiments on an IPMSM with low saturation effect.

A wide-speed-range sensorless control for an IPMSM is deeply studied in this paper, which combines the high-frequency injection (HFI) method and sliding-mode observer (SMO) method. At low-speed range, a rotating high-frequency voltage signal is injected into the IPMSM; the rotor position can be estimated by the HFI method based on the saliency of the IPMSM. At high-speed range, an SMO method based on the extended back electromotive force (EMF) of the IPMSM is utilized to estimate the rotor position. Furthermore, to blend the positions estimated by these two methods, a speed-dependent weight function is designed. The steady-state and dynamic performance of the wide-speed sensorless control are investigated by experiments. In high-speed range, the position estimation errors of the SMO method at different operation points are smaller than 6 el.deg.; in low-speed range, the position estimation errors of the HFI method at different operation points are smaller than 15 el.deg.; and during the transition process, the IPMSM can switch smoothly between the HFI-based and SMO-based sensorless control methods.

In order to solve the problem that the three-phase current of the interior permanent magnet synchronous motor (IPMSM) contains the 11th and 13th current harmonics, a multiple synchronous rotating frame transformation (MSRFT)-based current harmonic suppression method is established. Firstly, the influencing factors of current harmonics in IPMSM vector control are analyzed, and the influence mechanism of the inverter’s dead-time effect and the permanent magnet flux linkage harmonics on the current harmonics is described. Secondly, a simple current harmonic extraction method is proposed by optimizing the traditional current harmonic extraction method based on MSRFTs. The proposed method achieves the accurate extraction of the current harmonic components. Thirdly, a harmonic voltage generation method is established and is combined with the proposed current harmonic extraction method to form a current harmonic suppression strategy. Finally, the feasibility and effectiveness of the proposed method are verified via MATLAB/Simulink simulations and experiments. The simulation and experimental results show that the proposed current harmonic extraction method can extract the current harmonic components accurately, and the proposed current harmonic suppression strategy can suppress the 11th and 13th current harmonics effectively.

At present, most of the existing control strategies of motor drive system are based on the motor itself, without considering the electric vehicle energy consumption from the perspective of the whole vehicle. Hence, a motor drive system control strategy for electric vehicle energy consumption is proposed in this paper. Combining the electric vehicle driving state with the control of interior permanent magnet synchronous motor (IPMSM), the maximum torque per ampere (MTPA) control strategy of electric vehicle IPMSM based on optimization acceleration curve is established. Then, the proposed method is verified by both Matlab/Simulink simulation and experiment. The simulation and experimental results show that compared with the NEDC urban conditions, the driving range of the electric vehicle drive system control strategy based on optimization acceleration curve has been improved a lot, and the energy consumption per kilometer has also been reduced, which verifies the feasibility and effectiveness of the proposed control strategy.

This paper proposes a simplified near optimal control (NOC) scheme to reject the disturbances of interior permanent magnet synchronous motor (IPMSM) drives by minimizing the complex calculations in the Taylor series method required for solving the state-dependent Riccati equation (SDRE). Since the speed tracking performance of an IPMSM can be significantly degraded in the presence of the disturbances owing to the practical factors (e.g., external load torque, parameter uncertainties, and so on), an SDRE-based near optimal disturbance observer (NODO) is designed to accurately estimate and reject the disturbances associated with the speed and current in the feedforward control. The state-dependent coefficient matrices of the IPMSM are rearranged in the controller and observer to minimize the complex offline calculations of the Taylor series method used to solve the SDRE. By significantly simplifying the calculations, the proposed SDRE-based NOC scheme can be efficiently applied to the IPMSM drives. To verify the precise and robust control performance of the proposed NODO-based near optimal speed controller, experiments are conducted via a prototype IPMSM drive system with a TI-TMS320F28335 DSP under different disturbances. Finally, the comparative experimental results with the conventional NOC are presented under load change and wide speed range conditions.

Efficiency of an IPMSM motor is influenced by the operating point (OP) of the machine. The optimal operating point can be found by using either direct search methods or model-based methods. Model-based methods are sensitive to parameter uncertainties of the equivalent circuit of the drive. In this paper, the impact of various parameter estimation methods on the motor efficiency is compared. Studied methods are Recursive Least Squares (RLS), frequency domain identification at standstill, and the flux linkage map method. Results are compared to direct search methods, where the efficiency is evaluated using the power consumption measurement and direct measurement of the torque. Comparison is performed on a grid of various setpoints (currents and speed). The RLS is tested in two versions of linearization of the flux: one using only the inductances, the second estimating also their offset. Each method is able to obtain good results for some OPs and bad results for other OPs. Overall, good performance was obtained for direct search, offline identified parameters and flux linkage map and RLS with flux offset. RLS without the flux offset does not yield consistent results which implies significantly lower efficiency.

Considering the low reliability and poor adaptability of existing drum shear cutting parts, this paper presents a permanent magnet short-range cutting transmission system with a low-speed and high-torque interior permanent magnet synchronous motor (IPMSM) as the driving source and a sensorless control strategy based on a new sliding mode observer (SMO). To increase the robustness of the observer and reduce the error caused by chattering in the traditional SMO, the phase-locked loop technique is used instead of the traditional arc-tangent function estimation, and the sigmoid function is introduced to replace the traditional sign function; then, the sliding mode gain is adjusted through the fuzzy control algorithm in the new SMO. The scheme effectively improves the problems of the high failure rate caused by the long transmission chain of the shearer cutting section and the environmental impact for the mechanical sensor measurement results. Finally, the mathematical model of IPMSM based on the two-phase rotating coordinate system and end cutting load is established to verify the effectiveness and feasibility of the program. The results show that the new observer can accurately realize the speed and position estimation of the shearer cutting motor, and it has good dynamic response performance, observation accuracy, and robustness.

The active vector effects on torque and flux linkage are different in interior permanent magnet synchronous motor (IPMSM) systems at different times under direct torque control (DTC). These different effects may cause overcompensation or undercompensation to torque and flux linkage leading to large torque and flux linkage ripples in the IPMSM DTC systems. A novel duty ratio modulation strategy for the IPMSM DTC systems is presented, which considers these differences that are ignored in conventional duty ratio modulation strategies. The proposed duty ratio modulation strategy aims at minimizing torque ripple and flux linkage ripple, which makes sure that the control system can work in an optimum state. The active angle, the impact angle, the active factor, and the impact factor are first introduced. The active angel and the impact angle are used to get the active factor and the impact factor, respectively. Every sector is divided into five small sectors based on the impact angels, and then, a switching table is redesigned according to the small sectors division. Also, the vector selection rules for the redesigned switching table are described in details. Subsequently, an optimal duty ratio can be derived through the simplified duty ratio determination method. Finally, the effectiveness of the proposed novel modulation strategy is verified through the experimental results on a 100-W IPMSM drive system.

application/pdf, Article, 英文学会誌D：IEEJ Journal of Industry Applications. 2017, 6 (6), p.401-408

In this paper, the Novel Immune Algorithm (NIA) is proposed for an optimal design of electrical machines. By coupling the conventional Immune Algorithm and Steepest Descent Method, the NIA can perform fast and exact convergence to both global solutions and local solutions. Specifically, the concept of an antibody radius is newly introduced to improve the ability to navigate full areas effectively and to find new peaks by excluding already searched areas. The validity of the NIA is confirmed by mathematical test functions with complex objective function regions. The NIA is applied to an optimal design of an interior permanent magnet synchronous motor for fuel cell electric vehicles and to derive an optimum design with diminished torque ripple.

This paper deals with efficient operation method for the electromechanical brake (EMB). A three-phase interior permanent magnet synchronous motor (IPMSM) is applied to the EMB operation. A current controller, speed controller, and position controller based on proportional-integral (PI) control are used to drive the IPMSM. Maximum torque per ampere (MTPA) control is applied to the current controller to perform efficient control. For MTPA control, the angle &beta, is calculated from total input current, and the synchronous frame d&ndash, q axis current reference is determined by the angle &beta, The IPMSM is designed and analyzed with finite element analysis (FEA) software and current control is simulated by Matlab/Simulink using a motor model designed by FEA software. The simulation results were verified to compare with experimental results that are input current and clamping force of caliper. In addition, the experimental results showed that the energy consumption is reduced by MTPA.

International audience; In this paper, a nonlinear high order sliding mode (HOSM) controller and an adaptive interconnected observer for sensorless interior permanent magnet synchronous motors (IPMSM) are designed. A maximum-torque-per-ampere strategy (MTPA) is used to compute direct rotor current reference. The high order sliding mode controller is designed in order to ensure finite-time convergence of sliding variables and its high order time derivatives despite parameter uncertainties and unknown load torque. The adaptive interconnected observer estimates the currents, the angular velocity, the position, the load torque and the stator resistance. By Lyapunov theory, the observer-controller stability is proved. Simulation results confirm the effectiveness of the proposed method.

Finite-control-set model predictive current control (FCS-MPCC) has been widely investigated in the field of motor control. When the discrete motor prediction model is not obtained accurately, prediction error often occurs, which can result in improper determinations of optimal voltage vectors and can further affect the control performance of motor systems. However, papers evaluating the motor control performance employing FCS-MPCC rarely consider prediction error and its utilization to weaken the influence of inaccurate prediction model. This paper investigates in depth the prediction error caused by three influencing factors from the perspective of model accuracy—discretization method, prediction stepsize, and parameter mismatch. Firstly, the evaluation index, prediction error, is defined and its formulas considering the above three factors are derived based on interior permanent magnet synchronous motor (IPMSM). Then, the theoretical analysis of prediction error is provided. Finally, experimental results of an IPMSM drive system are presented to verify and complement the theoretical analysis. Both the theoretical analysis and experimental results fully elaborate the prediction error, which can offer practical guidelines for the evaluation and improvement of motor control performance, especially for FCS-MPCC in IPMSM applications.

Neste artigo é apresentado o controle linear de torque de um motor síncrono de ímãs permanentes interiores funcionando nas regiões de torque constante e de potência constante. O controle de torque constante é implementado através da curva de máximo torque por Ampère do motor. A tensão de terminal do estator é mantida constante ao longo da região de enfraquecimento mediante o controle da reação de armadura. Para melhorar a resposta dinâmica do controle, o controle de máximo torque por Ampère é estendido à região de enfraquecimento parcial de campo, que é uma região intermediária de velocidade. Resultados de simulação computacional e experimentais são obtidos com o objetivo de validar os métodos de controle propostos. In this article is presented the linear torque control of an interior permanent magnet synchronous motor operating in the constant torque and field weakening ranges. The constant torque control is implemented by using the maximum torque per Ampère curve of the motor. The terminal stator voltage remains constant along the field weakening range by controlling the armature reaction control. In order to obtain a better dynamic response, the maximum torque per Ampère control is extended up to the field weakening range, called partial field weakening region. Experimental and simulation results are presented in order to validate the proposed torque control methods.

Generally, design of the parts of an automobile is restricted by space especially components assembled in the engine room. Therefore traction motor for hybrid electric vehicle is designed by interior permanent magnet synchronous motor (IPMSM). The IPMSM has high power density and efficiency because it generates not only magnetic torque but also reluctance torque. However, IPMSM is difficult to design due to magnetic saturation and lots of analysis methods are required. Equivalent circuit analysis (ECA) is one of the design methods of IPMSM and it is generally used for characteristics analysis. Using the ECA, we can calculate the characteristics quickly. However, ECA can not estimate line current exactly because of saturation of magnetic core and flux weakening control. In order to perform the ECA exactly, calculation of parameters such as phase resistance, d- and q-axis inductance and no-load linkage flux are important. The phase resistance is simply calculated by using linear equation which is geometrical problem. However, dand q-axis inductance is nonlinear problem which is varied with current level and current angle. Therefore, nonlinear finite element analysis is necessary. Conventional ECA is considered only d- and q-axis inductance profile but no-load linkage flux is considered as constant value. However, no-load linkage flux of IPMSM is also varied according to current level and current angle similar with d- and q-axis inductance profile. Therefore, no-load linkage flux profile which is calculated case of current level and current angle should be considered in the ECA. In this paper, the calculation method of no-load linkage flux profile is introduced firstly and then characteristic of specific model is analyzed with proposed method. The result of line current from improved ECA is compared with experimental result and result of conventional ECA.